Merck and KalVista sign diabetes drug pact

Merck & Co. will pay $9 million for a 9.9% stake in the protease inhibitor developer KalVista Pharmaceuticals. Merck is also giving KalVista $37 million up front for its lead drug candidate, a small-molecule inhibitor of an inflammation-activating enzyme called plasma kallikrein. The drug, which aims to alleviate fluid buildup in diabetic macular edema, requires an injection directly into the eye. A potential $715 million in milestone payments could come to KalVista as the firms work on oral plasma kallikrein inhibitors.